Perhaps the most difficult problem in the career of Moss Evans, who has died aged 76, was his inheritance. He succeeded to the general secretaryship of the Transport and General Workers Union (TGWU), the most politically influential union in Britain, following four names engraved in labour history, Ernest Bevin, Arthur Deakin Frank Cousins and Jack Jones.

Evans refused to be intimidated but it was a rough passage. He was at the pivotal point of resistance during the 1978-79 winter of discontent which led to the collapse of James Callaghan's Labour government.

Some members of the Callaghan cabinet still attribute much of the responsibility for that Labour disaster to the chubby, loquacious Welshman. The most outspoken criticisms come in the memoirs of Lords Healey and Callaghan - especially from Denis Healey in his The Time of My life (1990) in which he denounces Evans as "a very inadequate substitute for Jack Jones".

It was the time of the social contract; the government would offer concessions to the unions in return for moves to contain wage inflation. Jack Jones was one of the architects of that policy, but Evans succeeded Jones at the very moment when employers and shop floor workers were in revolt against wage restraint.

The Callaghan government and the TUC had placed too much weight on a policy that simply couldn't take the strain. Even if Evans had been an Ernest Bevin he would not have been able to hold the ring. His critics are unfair, but they may be on firmer ground in criticising his leadership style. At a crucial TUC meeting on November 14 1978, when the government was negotiating with union leaders on the social contract, he was on holiday. Healey marks that moment as the critical point of departure and "a triumph for Mrs Thatcher". Certainly, once back, Evans was at the forefront of most of the pay demands which led to the winter of discontent.

The strain of that period took a severe toll and Evans fell ill not long afterwards. For most of 1981 his deputy, Alex Kitson, was acting general secretary, presiding at the Labour party conference at which Tony Benn came within a fraction of defeating Healey for party deputy leadership. The TGWU voted for the late John Silkin, which some observers, described as "Moss's revenge" - even in his absence - on Healey.

Evans was a miner's son, born in the Welsh mining village of Cefn Coed near Merthyr Tydfil. His mother, originally widowed during the first world war, married Moss's father and bore 12 children. During the depression, his father was only occasionally employed so his mother took a job in a local brickyard.

For much of Evans's childhood the family remained on parish relief: the children slept four to a bed and often begged for bread from the posh houses across the valley. When Evans was 12, the family joined the 1930s Welsh migration and moved to Smallheath in Birmingham where his father found work. "My experience during my formative years was of living in a society which, quite frankly, believed in the law of the jungle," Evans recalled.

He was a bright pupil and sat for hours absorbing classics such as Robert Tressell's The Ragged Trousered Philanthropist and Jack London's The Call of the Wild. At 14 he moved to a Joseph Lucas factory where he joined the Amalgamated Engineering Union. Bombed out during the second world war, the family moved back to south Wales where Moss made machine-gun breech blocks for BSA. He began to take an active part in trade unionism. He was later recruited to work in Berkshire on the D-Day Mulberry Harbours - and met his wife Laura.

Back in the Midlands, in 1950 he took a job at the Bakelite company in Tyseley, joined the TGWU, became a shop steward, took day-release (unpaid) courses at Birmingham University and planned to go to Ruskin College, Oxford. But in 1956 he was accepted as a TGWU full-timer and appointed Birmingham east area official for the engineering and chemical industries, and in 1960 midlands region trade group secretary. His mentor was Jack Jones, then regional secretary for the TGWU's powerful Midlands area. When Jones became number three to Frank Cousins he brought Evans with him as national officer for the TGWU's engineering section.

The making of Evans as a negotiator and industrial peacemaker was his work as as chairman of the Ford national joint negotiating committee. It was also where his lifelong friendship was established with his successor as general secretary, Ron Todd.

Ford was plagued with unofficial strikes - in 1970 and 1971 there were two serious official stoppages, followed by unofficial action. Evans resolved these disputes and secured peace after a number of unofficial strikes at Ford's Merseyside and south Wales plants. In 1973 Jones appointed Evans as TGWU national organiser following his negotiations on a shorter working week for Ford's 50,000 workforce.

Already he was seen as a successor for Jones, but his problem was that the outstanding candidate was Harry Urwin, Jones' deputy and a brilliant leader who had been close to Jones for 30 years. But he was only two years younger than Jones and refused to run - arguing that he would have only two years in the job before he was forced to retire - unless Jones proposed a rule change. Jones wouldn't, which cleared the way for Evans.

So in April 1977, Evans won a majority of more than 200,000 over his nearest rival on a 40% poll of the union's 2m members and took over at the end of March 1978, aged 52, with the prospect of serving for 13 years - but he only remained for seven years. Illness had weakened him, and in 1984 Todd succeeded him, although the two men worked in harness until July 1985, when Evans finally retired on his 60th birthday.

Evans was still smarting from the criticism of his role during the winter of discontent. He was particularly wounded by the frequent speculation about what might have happened in 1979 if Urwin, and not he, had succeeded Jones. Remarkably, in Jones's 1986 autobiography there is no mention of Evans, despite the latter having tried to continue with Jones's general policies.

Evans was a member of the TUC General Council (1977-1985) and on the National Economic Development Council (1978-1984). He described himself as a "man of the shop floor", he was a staunch socialist but not an ideological theorist, a man who regarded trade unionism as the cornerstone of representative democracy for working people. That was why, when the social contract was collapsing under rank and file pressures Evans's allegiance was to shop-floor influences rather than the government's holy grail. The Callaghan cabinet never forgave him.

After his retirement, the Evanses left Hemel Hempstead for Norfolk. He became a King's Lynn Labour councillor and mayor of King's Lynn and West Norfolk in 1996. He also became a trustee of the 3R Centre, a charity he helped set up for abandoned racehorses.

The death of a son in an accident soon after his own illness profoundly affected him. He leaves his wife Laura, two sons, three daughters and 10 grandchildren.